When chewing is pricey

Earlier today I took Aj and Ki to TJ's grocery shopping. Suddenly, Aj was holding a $5.00 bill. When I asked him where he got it, he told me it had been in his pocket. Later, I let Aj go out front to watch for trains. I could see him and from a distance I noticed him put something in his mouth and begin to chew. Well, I hadn't given him any food. He wandered over then and I asked, "Aj what are you eating?!"
"Part of that $5.00."
"You are eating the $5.00?!"
"Not the whole thing, I put the rest in the trash."